Dental composites made from organic resins and filler are finding increasing use in dental applications, especially in restorative dentistry, due to their excellent aesthetic properties. Dental materials generally have unique requirements as compared to the broad spectrum of composite materials. For health reasons, dental materials should be suitable for use in the oral environment. In certain instances, durability of a dental material is important to ensure satisfactory performance. For example, high strength and durability is desirable for dental work that is performed at dentition locations where mastication forces are generally great. In other instances, aesthetic character or quality is highly desired. This is often the case where dental work is performed at locations where a tooth repair or restoration can be seen from a relatively short distance.
It is also generally desired that the dental restorative material blend well with the surrounding dentition and that the dental restorative material looks life-like. Aesthetic quality in dental materials is typically achieved by creating material that has tooth-like colors/shades. Many fillers, however, generally have less mechanical strength than is desired.
Translucency of a dental material is useful for esthetic reasons and for efficient UV curing of the resin. To achieve good translucency, it is desirable to minimize the scattering of light as it passes through the material. This may be accomplished by matching the average refractive index of the filler and the resin.